Calathea live on the forest floor in the rainforest. But only 2-5% of the rain that falls in a rainforest makes it to the forest floor. So they are basically growing in fairly dry medium. Because of this they have evolved 3 things that ensure they survive. Purple or maroon undersides with special cells that absorb green light that bounces up uff the forest floor, special cells on the undersides of the leaves that absorb moisture from the air through humidity, and the ability to lift their leaves and 'pray' at night to funnel whatever rain DOES make it to the floor directly to their rootball.
While it seems like you would water a Calathea that starts to brown and crisp on the leaf edges more, thinking it's being under watered,this is actually more harmful. It needs more humidity, which it can absorb, not more water in the pot.
Running a hot shower and making your shower cubical a mist chamber, or having an empty aquarium or other vessel you can make into a mist chamber, and setting the plant inside it a few times a week might solve your problem
